Method for detecting gross vehicle weight overload

Abstract

A method of detecting gross weight overload of a vehicle comprising the steps of positioning one or more ultrasonic sensors on the vehicle so that said sensors measure the distance to a ground surface, using the sensors to measure height above the ground surface of the vehicle in a non-overloaded condition, adding known weights to the vehicle until maximum gross vehicle weight (GVW) is attained, ascertaining height above the ground surface at this gross vehicle weight (GVW), and continuously measuring height of the ground surface and collecting height above the ground surface data to establish when an overload condition occurs.

What is claimed is: 
     
       1. Method of detecting gross vehicle weight of a vehicle, comprising the steps of:
 positioning a vehicle height sensor on the vehicle such that the sensor measures the distance to a ground surface; 
 loading the vehicle until the maximum gross weight of the vehicle is attained; 
 ascertaining from the output of the sensor the height above the ground surface corresponding to a minimum height above ground associated with a maximum gross vehicle weight; and, 
 indicating when the measured height is below said minimum height above ground; the vehicle having at least one additional sensor spaced from the first mentioned sensor and further including the steps of measuring the height above ground at each of the sensors to provide a baseline and subsequently measuring height above ground of the sensors and indicating when there is a predetermined difference in the height measurement between the baseline measurement and the subsequent corresponding measurement. 
 
     
     
       2. The method of  claim 1 , wherein the sensors include an ultrasonic sensor. 
     
     
       3. The method of  claim 1 , wherein the sensors include an optical sensor. 
     
     
       4. The method of  claim 1 , wherein the sensors include a dual beam IR sensor. 
     
     
       5. The method of  claim 1 , wherein the sensors include a focus/defocus range finding sensor. 
     
     
       6. The method of  claim 1 , and further including averaging the output of a sensor so as to establish a mean average height. 
     
     
       7. The method of  claim 6 , and further including the step of comparing the mean average height above ground to said minimum height above ground to determine that the maximum gross vehicle weight has been exceeded. 
     
     
       8. The method of  claim 1 , wherein the predetermined difference in height measurement corresponds to the tilt of the vehicle. 
     
     
       9. The method of  claim 8 , wherein the sensors are spaced transversely to the centerline of the vehicle. 
     
     
       10. The method of  claim 8 , wherein the sensors are spaced fore and aft to measure the fore and aft tilt of the vehicle. 
     
     
       11. The method of  claim 8 , and further including the step of providing an alarm indicating when the measured tilt exceeds a predetermined threshold. 
     
     
       12. A method for measuring a predetermined condition of a vehicle comprising the steps of:
 measuring the height of the vehicle above a ground surface and the tilt thereof using two sensors; and, 
 determining when the measured height and tilt is outside a predetermined range; the vehicle having at least one sensor snared from the other of the two sensors and further including the steps of measuring the height above ground at each of the sensors to provide a baseline, subsequently measuring height above ground of the sensors and indicating when there is a predetermined difference in the height measurement between the baseline measurement and the subsequent corresponding measurement. 
 
     
     
       13. The method of  claim 12 , wherein the predetermined range includes a range corresponding to an unsafe condition. 
     
     
       14. The method of  claim 12 , wherein the predetermined range is an out-of-specification range. 
     
     
       15. The method of  claim 12 , wherein the sensed height is due to vehicle loading and wherein an alarm condition is initiated when the sensed height of the vehicle is a below a minimum height threshold. 
     
     
       16. The method of  claim 15 , wherein the minimum height threshold is that associated with a maximum allowable gross vehicle weight. 
     
     
       17. Apparatus for measuring a predetermined condition of a vehicle comprising:
 a pair of sensors for measuring the height of the vehicle above a ground surface and the tilt thereof; and, 
 a unit determining when the measured height and tilt is outside a predetermined range; the vehicle having at least one of said sensors spaced from the other of said pair of sensors, said unit measuring the height above ground at each of the sensors to provide a baseline and subsequently measuring height above ground of the sensors and indicating when there is a predetermined difference in the height measurement between the baseline measurement and the subsequent corresponding measurement.